Mining machine



E. F. MULLER MINING MACHINE Feb. 13, 1934.

Filed May 29, 1930 Patented Feb. 13, 1934 oirso STATES MINING MACHINEErnst F. Muller, Columbus, Ohio, assignor to The J eifrey ManufacturingCompany, Columbus, Ohio, a corporation of Ohio Application May 29, 1930.Serial No. 457,327

2 Claims.

The present invention relates particularly to mining machines of theso-called Arcwall type wherein a turntable is mounted at the forward endof a truck for rotation about a substantially vertical axis andhasmounted thereon an elongated cutter bar which is adapted to engage acoal face in front of the machine in the wellknown manner to form anarcuate cut or which may be positioned in laterally projecting relationto the machine to form a longwall cut.

Machines of this general type have long been in use and the mountingmeans provided for the turntable has heretofore been suflicientlyadequate. With the development of the machine 5 as at present, however,due to the greater weight which the turntable is called upon to support,much of which projects beyond the bounds of the turntable and thusexerts a distortive effect thereon. It has been found that there is adisproportionate loss of power due to friction.

The well-known Jefirey Arcwall machine of the prior art, for example,comprises a wheel mounted truck provided forwardly with three verticallyextensible and retractible pedestals which support a ring upon which theturntable is mounted. The ring has mounted thereon on radial axes anumber of rollers which engage the lower surface of the turntable tosupport the latter for rotation about a substantially vertical axis.Supported beneath the turntable for rotation about axes perpendicular tothe turntable surface are a number of rollers which engage the innerface of the ring to prevent displacement of the turntable in the radialdirection of the ring. Further, depending from the lower tumtablemargins are a number of brackets having angular portions extending underand adapted to engage the lower face of the ring to prevent tilting ofthe turntable relative to the ring. In practice these various mountinginstrumentalities develop large frictional resistance and for thisreason impair the general efficiency of the machine.

According to the present invention I provide novel anti-frictionmounting means for the turntable whereby its turning resistance isreduced to a minimum.

In the accompanying drawing I have shown a preferred embodiment of theinvention, although it will be understood that I do not restrict myselfto this illustrative showing.

In the drawing:

Figure 1 is a plan view of a Jeffrey Arcwall" machine provided withanti-friction turntable supporting means in accordance with the presentinvention,

Figure 2 is a section on line 2-2 of Figure 1, and

Figure 3 illustrates a detail.

Referring to the drawing, reference numeral 5 designates generally awheel mounted truck adapted to be positioned on a mine track to bepropelled thereover by self-contained motive devices. Mounted on threeupright pedestals 6 is a ring 7, Figure 2, which is normally supportedin horizontal position in which it may be raised or lowered by equalextension or retraction of the pedestals, or, if desired, it may betilted by differential extension and retraction of the pedestals.

Reference numeral 11 designates the turntable whose margins overlie theupper face of ring 7. The upper face of the ring and the lower marginalportion of the turntable are provided with opposed grooves 8 and 12,respectively, developed on equal radii about the ring axis as center,and in these grooves are arranged anti-friction members such as balls10. A relatively thin spacer ring 13 is disposed intermediate ring 7 andthe turntable and is provided with spaced apertures receiving andmaintaining balls 10 in properly spaced relation. Spacer ring 13 ispreferably made up of a number of segments 13a, Figure 3, these segmentsbeing preferably joined together at their abutting ends as by welding,although they may be disposed merely in freely abutting relation.

Inwardly of groove or race 12 a number of brackets 14 are secured independing relation to the turntable immediately within the ring, andextend substantially to the bottom of the latter. Brackets 14 are spacedon a common circle concentric with the ring axis and at their lower endssupport an annulus 15 which underlies the lower face of ring '7. Theupper outer margins of annulus 15 are rabbeted as shown in Figure 2, andprovided with a groove 16 opposed to a groove 9 in the bottom face ofring 7, these two grooves being developed on equal radii from the ringaxis, and engaging balls 17 between them, the balls being maintained inspaced relation by means of the spacing ring 18 similar to spacing ring13 above described.

Balls 10 transmit the weight of the turntable to ring '7 and areretained in their races due to the engagement of the lower face of thering by annulus 15 through the intermediary of balls 17, the latterpreventing tilting of the turntable relative to the ring. Due to thesecure engagement of both sets of balls within their races, they act toprevent radial displacement of the turntable relative to the supportingring.

Due to the above provisions, the turntable is supported for freerotation relative to the supporting ring while at the same time itsbodily movement relative to the latter is effectively prevented. Assliding friction of the supporting and guiding elements is practicallyeliminated, there is less requirement for lubrication and attention thanin the old construction.

While the upper and lower races of ring '7 and the upper turntable raceare shown as being formed directly in those members, it is obvious thatthey might be formed in separate annular elements secured in properrelation to the parts.

Although I have described a specific embodiment of my invention, it willbe understood that I do not limit myself to structure except as setforth in the following claims.

I claim:

1. In a mining machine, a support, a substantially horizontal ringmounted on said support, a turntable having a circular portion overlyingthe upper face of the ring, a horizontally projecting cutter bar mountedon the turntable, means for swinging the turntable relative to the ring,balls interposed between said circular portion and said upper face tosupport the turntable for rotation relative to the ring, a plurality ofcircumferentially spaced brackets depending from and bolted to theturntable, an annular member bolted to and supported by said brackets inunderlying relation to the lower face of said ring, and balls engagedbetween the lower face of the ring and said annular member to preventtilting of the turntable relative to the ring.

2. In a mining machine, a support, a substantially horizontal ring abovesaid support and having its top and bottom faces provided withcontinuous grooves, means between the support and ring adjustable toadjust the ring translationally relative to the support or to tilt itrelative to the latter, a turntable having a circular portion overlyingthe upper face of the ring and a circular portion underlying the lowerface of the ring and means rigidly connecting said circular portions, ahorizontally projecting cutter bar mounted on the turntable, means forswinging the turntable relative to the ring, said circular portionsbeing provided with grooves opposed to and registering with the top andbottom grooves of said ring, and balls in said grooves to support theturntable for rotation relative to the ring and to prevent tilting andradial displacement relative to the ring.

ERNST F. MULLER.

